NATIONWIDE — Law enforcement officials are asking people be on heightened alert Friday after cities across the country received emailed bomb threats.

Although the emailed threats — many of which claimed a hidden bomb would detonate unless $20,000 was transferred to the sender's Bitcoin account — appear to be a hoax, security experts said that people should still take precautions.

The threats were made against businesses, organizations, even schools, across the country, including Florida. Many of the institutions were evacuated as a precaution.

"I write you to inform you that my man hid the explosive device in the building where your company is conducted," a threatening email sent to Dave Benson's Orlando business said.

"Actually, in the title, it was, 'Don't play with me,'" said Benson, who runs a security consultant business and he could tell it was a fake.

"It's pretty consistent with other scams we've seen, albeit not as widespread. I understand this is country-wide," he said.

Penn State University notified students via a text alert about threats to a half-dozen buildings and an airport on its main campus in State College, Pennsylvania. In an update, the school said the threat appeared to be part of a "national hoax."

Email threats were also sent to at least one city in Canada, according to CNN. Vancouver Police confirmed to the news network that several businesses there received them.

Back in the U.S., CareerSource locations in Ocala, Sanford and Orlando, Florida received the bomb threats, as did the Bank of America building in downtown Orlando.

Florida's Tampa Police Department responded to eight bomb threats, including an email sent to Channelside Academy.

Now, the search is on for those responsible.

"I wouldn't even rule out that it's not from somewhere overseas, someone that English would not necessarily be their primary language, the way it was written," Benson said.

The FBI sent out a tweet after the threats came in, reminding the public to "Remain vigilant and to promptly report suspicious activities which could represent a threat to public safety."

Thursday's scare came less than two months after prominent Democratic officials and CNN’s Manhattan offices were targeted with package bombs. The suspect in that case, Cesar Sayoc, is in jail while awaiting trial.

The Associated Press contributed to this story.

Map: Locations where threats were received